The difference between a geotechnical study and a geotechnical expert report is not one of size. They are different documents, required in different situations, and the code sets three numeric thresholds that decide which.
The context is authorising amenajare works, and the full list of complementary documentation is in article 289 paragraph (2). What goes into the building-permit dossier itself is on the PAC page.
The thresholds
A geotechnical expert report is required in three situations, under letter b):
- when the necessary excavation goes deeper than 6 m, measured from natural ground level;
- when works are carried out on difficult foundation ground, on a slope with landslide potential;
- when retaining walls higher than 3 m are built.
Below those thresholds, letter a) asks for the geotechnical study. The figures are written in the law, not inferred.
The loop most people miss
The text does not stop at the expert report. If it recommends slope-support elements or improvement of the foundation ground, then for authorisation a geotechnical and structural study is submitted, describing the designed solution in principle, without detailing it.
So in the hard case you end up filing both, and the second document comes after the first and depends on its conclusions. That is sequencing, not bureaucracy: you cannot commission both on the same day, and you cannot estimate the timeline before knowing what the report recommends.
Without detailing is not a loophole
The wording limits what is required for authorisation, not what gets built. The detailed solution belongs to the next phase, the technical execution project. Commissioning a full support design at permit stage pays for a phase that cannot yet be finished.
What we check first
Excavation depth against natural ground level rather than finished level, and the height of the retaining walls. Two numbers move a dossier from one category to the other, and both are known at concept stage. The boundary between authorisation and execution is in the permit project is not the build project, the drawing that accompanies them is in the site plan, and the order they arrive in is in the order of the steps. For interventions on existing buildings, where diagnosis comes before the solution, see technical expert reports.
This article is analysis, not legal advice. The provisions cited are from Legea 169/2026, published in Monitorul Oficial no. 661 of 10 August 2026. Check your own situation with the issuing authority.